PET shows how vagus nerve stimulation works in depression

A study using PET imaging has found that vagus nerve stimulation, a procedure that involves implantation of an electronic stimulator in the brain to address treatment-resistant depression, can cause shifts in metabolic activity weeks or months before symptoms improve. PET scans were conducted prior to the procedure and then at three and 12 months following the initial stimulation, according to the study in Brain Stimulation. The imaging revealed metabolic shifts as well as changes to structures deep in the brain several months after the initiation of treatment.